Soybean (Glycine max L. Merr) is a major cash crop and investment commodity in North America and elsewhere. Soybean oil is one of the most widely used edible oils, and soybeans are used worldwide both in animal feed and in human food production. Iron deficiency chlorosis (IDC) in soybeans is a widespread problem in the Upper Midwest (North Central region) of the United States and is the result of reduced availability of iron and therefore, reduced iron levels in the plant. High pH in the soil, high water tables, too much rainfall, salinity in the soil, calcium carbonate in the topsoil, and elevated soil nitrate levels all contribute to the problem. The symptoms include interveinal chlorosis (the leaves turn yellow while the veins remain green) and stunting of plant growth. If the youngest leaves and growing points are damaged due to iron deficiency, growth of the plant will be stunted and yields are reduced substantially.
Different varieties of soybean vary in their sensitivity or tolerance to iron deficiency. Therefore, one of the most effective control measures is planting IDC tolerant soybean varieties, and thus varietal selection is important for the management of IDC. However, currently, determining whether a soybean cultivar might have tolerance to IDC typically involves testing each cultivar in the field or greenhouse under conditions that typically produce IDC. Thus, the present invention overcomes the shortcomings in the art by providing markers associated with tolerance to IDC, thereby allowing the characterization of soybean cultivars for IDC tolerance by molecular analysis rather than phenotypic analysis.